We randomly assigned 4589 healthy nulliparous women who were 13 to 21 weeks pregnant to receive daily treatment with either 2g of elemental calcium or placebo for the remainder of their pregnancies. Calcium supplementation did not significantly reduce the incidence or severity of preeclampsia or delay its onset. Additional analyses utilizing the study database and specimen repository are being performed. During FY07 papers were published on the relationship of sequential change in antiangiogenic factor concentrations in early pregnancy and risk of developing preeclampsia, on angiogenic factors in preeclampsia, and on the neonatal oucomes of pregnancies delivered at 35, 36, and 37 weeks, comparing those with preeclampsia or gestational hypertension those of normotensive women. Work on angiogenic factors and preeclampsia is continuing.